1121443991 has 2 divisors, whose sum is σ = 1121443992. Its totient is φ = 1121443990.

The previous prime is 1121443957. The next prime is 1121444021. The reversal of 1121443991 is 1993441211.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1121443991 - 2⁶ = 1121443927 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1121443391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 560721995 + 560721996.

It is an arithmetic number, because the mean of its divisors is an integer number (560721996).

Almost surely, 2^1121443991 is an apocalyptic number.

1121443991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1121443991 is an equidigital number, since it uses as much as digits as its factorization.

1121443991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 35.

The square root of 1121443991 is about 33487.9678541413. The cubic root of 1121443991 is about 1038.9449331535.

The spelling of 1121443991 in words is "one billion, one hundred twenty-one million, four hundred forty-three thousand, nine hundred ninety-one".